Observation of SQUID-like behavior in fiber laser with intra-cavity epsilon-near-zero effect

TL;DR

This paper demonstrates a fiber laser system with epsilon-near-zero nanolayers that mimics SQUID behavior, offering new insights into ultrafast ENZ photonics and potential on-chip nanophotonic device design.

Contribution

It introduces a novel fiber laser setup with ENZ layers that emulates RF-SQUID behavior, bridging photonics and superconducting quantum systems.

Findings

Optical wave circulates akin to supercurrent in RF-SQUID

Different ENZ wavelengths produce distinct spectral outputs

ENZ elements lower optical potential barriers for specific frequencies

Abstract

Establishing relations between fundamental effects in far-flung areas of physics is a subject of great interest in the current research. We here report realization of a novel photonic system akin to the radio-frequency superconducting quantum interference device (RF-SQUID), in a fiber laser cavity with epsilon-near-zero (ENZ) nanolayers as intra-cavity components. Emulating the RF-SQUID scheme, the photonic counterpart of the supercurrent, represented by the optical wave, circulates in the cavity, passing through effective optical potential barriers. Different ENZ wavelengths translate into distinct spectral outputs through the variation of cavity resonances, emulating the situation with a frequency-varying tank circuit in the RF-SQUID. Due to the presence of the ENZ element, the optical potential barrier is far lower for selected frequency components, granting them advantage in the gain-resource competition. The findings reported in this work provide a deeper insight into the ultrafast ENZ photonics, revealing a new path towards the design of nanophotonic on-chip devices with various operational functions, and offer a new approach to study superconducting and quantum-mechanical systems.